Investigation of complex formation between Ce3+ ion and 4, 4’-bipyridine-dipicolonic acid proton transfer system in aqueous solution

In this study the stabilities of proton transfer systems and the complexation equilibrium of binary and ternary complex of pyridine 2٬6 dithiocarboxcilic acid or dipicolonic acid (pydc) and 4, 4′-bipyridine (bpy) with Ce3+ has been studied by potentiometric method all steps of titrations carried out in 25.0±0.1 ˚C and I=0.1 M NaNO3 Ligands’ protonation constants and stability constants of proton transfer and their metal complex were evaluated by computer refinement of the pH- Volume titration data using the BEST computer program. The distribution diagram of all systems as a function of pH was depicted by using Hyss 2009 program and the results compared with its X-ray crystal structure in solid state. The stoichiometry of the most complex species in solution was found to be similar to the crystalline complex